The nailing of fractured bones is taught in U.S. Pat. Nos. 2,397,545; 3,759,257; 3,986,504; 4,091,806; 4,204,531; 4,227,518; 4,237,875; 4,275,717 and German Pat. Nos. 2,117,604; 2,166,339; and 2,821,785.
The devices taught in these references do not rigidly hold a fracture distal to the femoral isthmus or permit weightbearing with dynamic compression. This is because such devices provide either (a) a fixed, rigid compression force or (b) a deploying mechanism which only guards against rotation. None of the reference teach the sliding upward of a distal locking device to allow ambulation and weightbearing which results when varying compressive forces are applied to the bone.
Further, none of the references disclose a distal lock mechanism comprising at least substantially flat blades which have outer sharp edges which engage a bone when the front end of each blades pivots outwardly about an axis orthogonal to the plane of each respective blade.